Using this tag in a page tells all other html taglib tags to render themselves as XHTML 1.0. This is useful when composing pages with JSP includes or Tiles. <html:html xhtml="true"> has a similar effect. This tag has no attributes; you use it like this: <html:xhtml/>.
Note: Included pages do not inherit the rendering style of the including page. Each JSP fragment or Tile must use this tag to render as XHTML.